Microfluidics involves micro-scale devices that handle small volumes of fluids. Because microfluidics can accurately and reproducibly control small fluid volumes, in particular volumes less than 1 μl, it provides significant cost-savings. The use of microfluidics technology reduces cycle times, shortens time-to-results, and increase throughput. Furthermore incorporation of microfluidics technology enhances system integration and automation.
An exemplary microfluidic device involves liquid bridge technology. Liquid bridges allow sample droplet formation or mixing utilizing immiscible fluids. In a liquid bridge, a sample droplet at an end of an inlet port enters a chamber that is filled with a carrier fluid. The carrier fluid is immiscible with the sample droplet. The sample droplet expands until it is large enough to span a gap between inlet and outlet ports. Droplet mixing can be accomplished in many ways, for example, by adjusting flow rate or by introducing a second sample droplet to the first sample droplet, forming an unstable funicular bridge that subsequently ruptures from the inlet port. After rupturing from the inlet port, the mixed sample droplet enters the outlet port, surrounded by the carrier fluid from the chamber. At that point in time, the droplet may be analyzed or undergo further manipulation, for example PCR amplification, QPCR, or immunoassay.